The present invention relates to a jack apparatus, and more particularly to a jack apparatus for lifting an aircraft having snow skis.
It is sometimes necessary to lift an aircraft off the ground during manufacture and/or the life of the aircraft. During manufacture, for example, an aircraft may need to be lifted for making final alterations to landing gear or an underside of the aircraft. One reason to lift an aircraft during its life is to make repairs, such as fixing a flat tire.
A common device used to lift aircraft is a tripod jack. Tripod jacks generally include a single aircraft interface point extending above a three legged base. Many aircraft require concurrent use of two or more tripod jacks to lift them. For example, to lift a fuselage of a helicopter, two tripods are usually used, where each tripod contacts one of two jack lifting points on the fuselage. In such applications, tripod jacks are positioned below the helicopter and between the landing gear so their bases do not interfere with each other and the landing gear.
Use of traditional tripod jacks for lifting aircraft has drawbacks. One drawback is the amount of time and energy required to lift the aircraft. For example, when two or more tripod jacks are used to lift the aircraft, an operator usually must incrementally raise each jack a small amount and repeat the incremental raising until the aircraft is lifted. This practice is time and energy intensive. Another drawback of using multiple tripod jacks to lift aircraft is the lack of space to position two tripod jacks as required to lift the aircraft when add-on items are attached. For instance, when snow skis are attached to the landing gear of some helicopters, the amount of space between the skis is insufficient to accommodate the bases of two adjacent traditional tripod jacks.